Process for producing-sulfuric-acid anhydrid according to the contact process.



recense poaraonncm'aemwuemn -.ecconnme moana www To all' whom it may concern se #new .1 and N'roN EINDED, doctorsf philosov i .1:1 chemists, citizens of the German Emplrf residing at Leverkusen, near Cologne-onthe-Rlnne, Germany, have-.invented new and useful Improvements inv Processes for Producing Sulfu icAcid Anhydrid According to the Contact Process, of-which the following is a spec' cation. v

- In spite of all eorts to replace platinum as catalyzer i n\the SO3 contact process thisv metal has proved to be indispensable. None .f

of' the many other contact substances proposed in suchLla'rge numbers, for instance ironoxid inthe shape of burnt pyrite,l iron oxid impregnated vvlth ferrous sulfate, oxids and sulfates or Cr Ni Co, Mn, U, Cu, oxygen compounds of l, Se, Zr, Ce, Di, La, Th, Ti, Si, vanadic acid, phosphoric acid, metals and oxids of the tantalum group, iron sueroxid-l-strontium oxid can c ompare in-its efficiency to platinum. The

velocity 'of thereaction produced by .these cal AWorking compounds does not suflice'for an economiof the contact rocess. Iron oxid alone of these catalyzers as been used to, some extent in practice and this body 'in -fact only vin combination- With platinum which converted into S08 the sulfurous acidy precedingiron oxid contact. c

We have now found that silver vanadium compounds are eminently suitable for replacingl thel platinum in the SQ,- contact process The excellent 'eiiciency' of this com- .binatio was the less to be'expected as pure i vanadic acideven when working very carefully allows at the best only a' conversion of 84 per cent. of the SO2 contained in the roaster ases into S08, andas on the other hand si ver, silver oxid and silver sulfate haveonly' a very small catalytic action on S02` and 0. On replacing silver by other metals,` such as Cu, Co, N1, U, Ti, Di, etc., the capacity .of conversion is in most cases even less than that of pure vanadic acid. rlhe surprising catalytic effect obtained by the combinations of silver and vanadium is so excellent, that on using-for instance an asbestos containing 2Ql per cent. of silver vanadate the sulfurous acid of the roaster gases is ahnos-quantitativelyoxidizedA to Spccilcatipn ov-e'ttersratent.- me 23,519.13..- -esanezzaa- A The reaction 'doesno't Adepend on ne tiles-0f Meme-013m limes@ denteameunt either? of vana" ium or vof silver, this may kinds of contact supports can, be used.

We claim:-

\ 1. The process of subjecting a mixture o gases, capable oilreactingv under the influence of a catalytic, to the action of a .contact substance comprising a contact support lmpregnated with a silver-vanadium compound.

gases, capable of reacting under the influence of a catalytic, to the action of a contact impregnated with a silver-vanadium compound. f y l 3. The process of subjecting a mixture of gases, capable of reactingunder the influence of a catalyticz to the action of a contact substance comprising a contact support i1n' pregrated with silver vanadate.

4. The process of subjecting a mixture of gases, capable of reacting under the influ- .substance comprls an asbestos support lmpregnated with si ,er' vanadate.

5. The process of subject-ingeJ mixture of gases, capable of; reacting under the indu'- ence of a catalytic, to the action .of a contact substance comprising an asbestos supvanadate. l

6. The process' ofroducing suluric-acid lanhydrid from sulr 'dioxid and oxygen fur dioxid and oxygen tothe.'4 action of a sllv'er-vanadium compoundas a.' contact substance. v IL .l

7. The process of producin sulfuric acid anhydrid from sulfur dioxi and loxygen whichcomprises subjecting 'a mixture ofI sulfur dloxid and oxygen to the action of' a vsilsuitable support.

8. The yprocess of .roducingsu'liiiric acid asbesteg, f f

9. 'llhl'e p -acess of producing sulfuric' aci-d Patented Jl'iglii 2.- The process of subjecting a mixture of' ence of a catalyti, tothe vaction of a contact i i which. comprises subjecting a mixture of sul`v `silver'-vanadiuin compounddistributed upon 'vary Within the Widest limits. All possible substance. comprising an asbestos support port impregnated with" about 20% 'silver ver-vanadium compound distributed upon a p anhydrid from sul r dioxid and oxygen j l' which comprises subjecting a mixture of sui.-`

vfur dioxid and oxygen to the action of silnver vanadate as' a contactsubstance.

10.y The process of producing sulfuric acid anhydrid from sulfuric dioxid'and oxygen furie` dioxidfand oxygen to the action of sil- Ver vanadate distributed upon a suitable support. v

l1. The process of producing sulfuric acid anhydridfrom sulfuric dioXid and oxygen silver vanadate distributed upon asbestos.

Awhich comprises subjecting a mixture of sulto the `action of 15 In testlmony whereof we have hereunto furic dioxid and oxygen set our-hands inthe presence ofl two sub` p scribing Witnesses. which comp-rises sub3ect1ng a mixture ofsul- HERMANN VON KEMER. [L 5.] ANTON WEINDEL. [my

Witnesses:

HELEN NUFER, ALBERT NUEE'R. 

